Cant send receive MMS?

I can send and receive sms but anytime I try and attach a image it will send then a few minutes later I get a message saying the message couldn't be sent. I tried with the normal sms and handcent sms apps although on handcent when I try and add a image it will keep loading and nothing happens, and get the could not be sent message, did some research and it is a issue with the app.

I have heard about turning off wifi and trying that but it didn't work, and I also make sure the image is under 1mb before trying to send.

I am on the everything data plan so I should be able to send MMS texts.